Tongue Stud Device Uses iPod to Drive Wheelchair

A wireless medical device places inside the mouth of quadriplegics enables them to use a computer and move their wheelchairs around.

The intraoral Tongue Drive System, developed by researchers at The Georgia Institute of Technology (Georgia Tech, Atlanta, USA), resembles a tongue stud, and it is composed of sensors placed on a dental retainer, which sits against the roof of the mouth, detecting the movement of a small magnet attached to the users' tongues. The sensor signals are then transmitted wirelessly to an iPod or iPhone that possesses software that enables the translation of the tongue commands, based on the magnet position. That data can then control a computer cursor or send a powered wheelchair in different directions.

The dental appliance contains magnetic field sensors mounted on its four corners, and also includes a rechargeable lithium-ion battery and an induction coil to charge the battery. The circuitry fits in the space available on the vacuum-molded acrylic retainer, and is covered with an insulating, water-resistant material. The researchers also created a universal interface for the device that attaches directly to a standard electric wheelchair and wirelessly receives the sensor data and delivers it to the iPod, connects the iPod to the wheelchair, charges the iPod, and includes a container where the dental retainer can be placed at night for charging.

The researchers recruited 11 individuals with high-level spinal cord injuries to test the headset version of the system. Trial participants received a clinical tongue piercing and tongue stud that contained a tiny magnet embedded in the upper ball. They repeated two test sessions per week during a six-week period that assessed their ability to use the Tongue Drive System to operate a computer and navigate an electric wheelchair through an obstacle course.

“During the trials, users have been able to learn to use the system, move the computer cursor quicker and with more accuracy, and maneuver through the obstacle course faster and with fewer collisions,” said associate professor Maysam Ghovanloo, PhD, of the Georgia Tech School of Electrical and Computer Engineering. “We expect even better results in the future when trial participants begin to use the intraoral Tongue Drive System on a daily basis.”

The intraoral Tongue Drive System was presented at the IEEE International Solid-State Circuits Conference, held during March 2012 in San Francisco (CA, USA).

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The Georgia Institute of Technology